The invention relates to a method for testing the fracture toughness of an adhesive joint to be formed between two components made of fiber-reinforced plastic (FRP) by forming a test joint between two sample elements and applying a tensile load onto this test joint until a pre-defined value is reached.
A number of variations of such methods are known. In one known tensile bond test, for example, two sample elements made of the same material as the components to be joined are adhered to one another, and the outer surfaces of the sample elements are joined by means of adhesive by one testing stamp in each case. By means of these testing stamps, a tensile force is applied to the samples, which is increased until either the joint breaks or a pre-defined limit value, seen as required for the adhesive force of the adhesive joint, is reached. Based on the test result, the strength of an adhesive joint formed between the components to be joined is determined.
In another known method, two sample elements are joined to one another by means of adhesive, and then, by introduction of a wedge element between the sample elements, the level of force that has to be applied to the wedge element in order to separate the samples from one another is determined.